The present invention relates generally to ventilation systems for motor vehicles, and more particularly to a ventilation system for a motor vehicle in which positive pressurization of the vehicle interior is accomplished along with particulate filtration of incoming air.
When motor vehicles are operated in geographical areas in which unimproved roads are common and in which the climate is often dry, dust clouds are unavoidably raised by air currents generated by the passing of the vehicle over the dry and dusty road surface. Large amounts of dust tend to infiltrate into the interior passenger or cargo compartments of vehicles under such conditions, quickly soiling the interior and being detrimental to the comfort and health of the occupants. This can be an especially acute problem in trailers, recreational vehicles, vans, and other large vehicles because of the many potential air entry points which can exist around windows, doors and various fittings.
It is relatively difficult to provide adequate sealing against air infiltration around doors and windows of trailers and recreational vehicles in an economical manner since the nature of the vehicle does not justify costly expenditures for sealing such as might be appropriate in a passenger automobile and the number of dust entry points is prohibitively large. Consequently, alleviation of the problem of dust infiltration preferably should be approached from a different perspective than that of merely improving the mechanical seal around obvious entry points such as windows. The present invention takes such a different approach.
It is desireable that prevention or alleviation of dust entry into a vehicle be accomplished despite imperfect seals around doors and windows and despite the presence of undesired but nevertheless inevitable small holes and cracks in the shell of the vehicle. The present invention makes this desire a reality.